Stream: fhirpath
Topic: Inaccuracy in docs at http://hl7.org/fhirpath
Alexey Slynko (Feb 25 2019 at 22:17):
Some pieces looks like an inaccuracy.
*5.5.1. iif(criterium: expression, true-result: collection [, otherwise-result: collection]) : collection
If criterium is true, the function returns the value of true-result parameter.
If criterium is false or an empty collection, the function returns otherwise-result, unless the optional otherwise-expression is not given, in which case the function returns an empty collection.*
There is no ref to otherwise-expression in function definition. May be, otherwise-result was meant.
*5.6.8. replaceMatches(regex : string, substitution: string) : string
If the input collection contains a single item of type string, the function will match the input using the regular expression in regex and replace each match with the substitution string. The substitution may refer to identified match groups in the regular expression.
This example of replace() will convert a string with a date formatted as MM/dd/yy to dd-MM-yy:*
Example reference points replaceMatches(), but not replace(), isn't it?
*6.5. Boolean logic
For all boolean operators, the collections passed as operands are first evaluated as booleans (as described in Boolean Evaluation of Collections). The operators then use three-valued logic to propagate empty operands.*
There is no section named Boolean Evaluation of Collections, but 4.5. Singleton evaluation of collections instead
Grahame Grieve (Feb 26 2019 at 01:30):
@Bryn Rhodes can we fix these before next ballot please
Bryn Rhodes (Feb 26 2019 at 02:31):
GF#20473 for the first one, thank you for the report. The other two have already been corrected.
Alexey Slynko (Feb 26 2019 at 08:59):
in http://hl7.org/fhirpath/2018Sep/ section 11 there is a ref to resolve() function:
*There are a few constructs in the FHIRPath language where the compiler cannot determine the type:
The children() and descendants() functions
The resolve() function
A member which is polymorphic (e.g. a choice[x] type in FHIR)*
But there is no function definition anywhere in spec
Alexey Slynko (Feb 26 2019 at 09:01):
And in appendix b there is a broken link to Pascal RI
Lloyd McKenzie (Feb 26 2019 at 15:33):
Can you submit a change request?
Alexey Slynko (Feb 27 2019 at 06:24):
But i can't resolve the situation. Does the resolve() function must be described, or it is obsoleted and removed from spec?
Lloyd McKenzie (Feb 27 2019 at 16:55):
@Bryn Rhodes
Bryn Rhodes (Feb 27 2019 at 19:05):
@Alexey Slynko , the resolve() function is not defined in the base FHIRPath spec, it is defined in the FHIR usage of FHIRPath here: http://hl7.org/fhir/fhirpath.html
Last updated: Apr 12 2022 at 19:14 UTC
